taming wp_upload_dir to create a directory with the name you want instead of a date

First I guess I need to answer “why” and there are probably two of them

Why do I care that it creates a date based directory even if not needed?Because I hate to waste CPU cycles if it can be avoided with almost no effort, and I hate to see empty directories when I need to traverse the uploads tree with an FTP software

Why not take the base directory from the value being returned and create the directory by myself?Because I prefer to trust the core APIs over my own code whenever possible. Core code is tested in real life by millions every day on different platforms and I will probably never test it on more then one. So while creating a directory seems like a very easy thing to do I sill prefer avoid thinking about the possible caveats that might be specific to a specific OS.

The code is actually easy, this is a snippet of something I work on right now